Battery and battery control method

Abstract

The present invention relates to a method for operating a battery, which includes determining the cell voltage of at least one battery cell, determining the associated cell pack voltage of the at least one battery cell, and evaluating the cell voltage and the cell pack voltage by means of an analysis program on a microprocessor in a main control unit, where an overheating warning message is triggered if, within a defined measurement period, the cell voltage decreases by a defined cell error value and the cell pack voltage decreases by a defined pack error value.

1 . A method for operating a battery which has a battery management system (BMS) having a main control unit comprising a main board, and comprising a plurality of cell packs, wherein a check with regard to a thermal event is carried out in regular measurement periods, wherein the following steps are performed:
 determining the cell voltage of at least one battery cell,   determining the associated cell pack voltage of the at least one battery cell,   evaluating the cell voltage and the cell pack voltage by means of an analysis program on a microprocessor in the main control unit, wherein an overheating warning message is triggered if, within a defined event time,   the cell voltage decreases by a defined cell error value and   the cell pack voltage decreases by a defined pack error value.   
     
     
         2 . The method according to  claim 1 , wherein the cell error value is at least 60%, compared with the cell voltage before the measurement period. 
     
     
         3 . The method according to  claim 1 , wherein the pack error value corresponds at least to the cell error value, plus/minus 10%. 
     
     
         4 . The method according to  claim 1 , wherein the event time during which after a cell error value a pack error value is determined is less than 3 s. 
     
     
         5 . The method according to  claim 1 , wherein the measurement period in the charging mode of the battery is in the range from 0.5 ms to 2 s. 
     
     
         6 . The method as claimed in  claim 1 , wherein the measurement period in the operating mode of the battery, in which a vehicle is driven by means of the battery, is in the range from 0.5 ms to 1 s. 
     
     
         7 . The method according to  claim 1 , wherein the measurement period in the idle mode of the battery, in which no vehicle is driven and no charging process is carried out, is above 10 ms. 
     
     
         8 . The method according to  claim 7 , wherein at least one further state measurement value is received and evaluated by the evaluation unit, and wherein at least one of: the measurement period and the frequency thereof is adapted on the basis of the at least one further state measurement value. 
     
     
         9 . The method according to  claim 8 , wherein at least one or more state values is taken from the following group:
 interval of time from the operating mode of the battery,   interval of time from the charging mode of the battery,   temperature of the battery, at least one of: during the respective measurement period and before the respective measurement period,   temperature curve of the battery before the respective measurement period, and   temperature in the outside area.   
     
     
         10 . A battery, in the form of a high-voltage battery (HV battery), comprising at least the following battery elements:
 a cell compartment having a plurality of cell packs and associated cells,   a main control unit having a main board, a main processor and a plurality of electronic elements, wherein   at least one pack measurement unit for the pack voltage is provided and   at least one cell measurement unit for at least one cell/cell voltage and a microprocessor which processes at least one of a digital measurement data and an analog measurement data by means of an analysis program.   
     
     
         11 . The battery according to  claim 10 , wherein the battery comprises at least one temperature sensor ( 7 ), wherein the temperature sensor is connected to the main control unit in a data-carrying manner. 
     
     
         12 . The battery according to  claim 10 , wherein comprising at least one pressure sensor ( 6 ), wherein the pressure sensor is connected to the main control unit in a data-carrying manner. 
     
     
         13 . The method according to  claim 1 , wherein the thermal event is a thermal runaway. 
     
     
         14 . The method according to  claim 1 , wherein the cell error value is at least 70% compared with the cell voltage before the measurement period. 
     
     
         15 . The method according to  claim 1 , wherein the pack error value corresponds at least to the cell error value, plus/minus 5%. 
     
     
         16 . The method according to  claim 9 , wherein the respective measurement period comprises a defined lead-in period, and wherein the temperature in the outside area comprises an expected temperature influence due to local conditions. 
     
     
         17 . The battery according to  claim 11 , wherein the battery-comprises at least one temperature sensor at or on at least one cell pack. 
     
     
         18 . The battery according to  claim 12 , wherein the at least one pressure sensor is a pressure sensor on or at least one cell pack.